vHIT and fHIT in Patients With Migraine, Vestibular Migraine, and Persistent Postural-Perceptual Dizziness

Objective: Impairment in the integration of different vestibular stimuli is the proposed mechanisms in vestibular migraine (VM). In this study, it was aimed to assess the vestibulo-ocular reflex (VOR) and dynamic visual acuity (DVA) in patients with VM and to compare the results with migraine without vestibular symptoms (MwoV), and persistent postural-perceptual dizziness (PPPD) to find out if there are discriminative differences and search for a correlation with the levels of anxiety. Methods: Twenty-two patients with MwoV, 23 patients with VM, 22 patients with PPPD, and 23 healthy controls (HC) were studied. Video head impulse test (vHIT) and functional head impulse test (fHIT) without and with an optokinetic background (OB) were performed. Percentage of correctly identified optotypes (CA%) was considered for the fHIT test. Beck anxiety inventory (BAI) was used to assess anxiety. Results: Lateral canal vHIT gain of the patient groups were not different from the healthy controls (p > 0.05). fHIT and fHIT/OB CA% results of all patient groups were lower than the HC (p < 0.005), and VM patients had the lowest scores for both tests. BAI scores of the PPPD patients were the highest and a correlation between anxiety levels, and fHIT results could not be identified (p > 0.05). Conclusion: Prominent CA% drop by the use of an OB was the main finding in patients with VM. This discriminative feature was not correlated with anxiety scores. Difficulty in resolving the conflict between visual and vestibular inputs seem to be the underlying mechanism. Level of Evidence: 3